1. Field of the Invention
The present invention principally relates to a car position detector for an elevator additionally disposed thereon to improve control performance upon the repair of an existing elevator.
2. Background Art
Referring to FIG. 6, a prior art car position detector for an elevator is illustrated, which is similar to an arrangement disclosed in Japanese patent publication No. Hei. 6-144734for example. The figure is an elevation view for, illustrating conceptually the construction of a portion of the elevator wherein designated at 1 is a car ascending and descending along a predetermined passage of a shaft 2, and 3 is a speed governor, disposed toward an upper part of the shaft 2.
Designated at 4 is an endless speed governor rope wound around a speed regulation pulley of a speed governor 3 and suspended in the shaft 2 with one side coupled with the car 1 to move, following the descending and ascending of the car 1. Reference numeral 5 shows a tension pulley mounted on a lower suspended portion of the speed governor rope 4 astride the rope to provide tension to the speed governor rope 4. Reference numeral 6 is an encoder coupled with a rotary shaft of the speed governor 3, and 7 is a position detection circuit, into which an output of the encoder 6 is inputted to detect the ascent and descent position.
In the prior art car position detector of an elevator arranged as described above, the speed governor rope 4 is moved and follows the ascent/descent motion of the car 1 to rotate the speed governor 3. Through the operation of the encoder 4 caused by the rotation of the speed governor 3, the ascent/descent position of the car 1 is detected on the basis of an output of the position detection circuit 7. The elevator can be controlled through a control panel (not shown) based upon the detection of the position of the car 1.
In the prior art car position detector of the elevator as described above, since the encoder is coupled with the existing speed governor 3, upon a repair of an existing elevator it is necessary to reconstruct the existing speed governor 3 of an encoder-equipped speed governor or to provide an additional coupling apparatus for the encoder on the existing speed governor 3. The prior art car position detector thus suffers from difficulties that it requires much complicated labor and that the connection of the encoder 6 is difficult to achieve because the space in the machine chamber where the speed governor 3 is installed is limited.
In view of the aforementioned difficulties of the prior art, it is an object of the present invention to provide an elevator equipped with a car position detection apparatus in which position detection apparatus can be additionally provided without requiring any repair of an existing speed governor.
According to one aspect of the present invention, an elevator comprises: a guide rail vertically installed in a shaft; a mount structure fastened to said guide rail; a transmission sheave attached to said mount structure; a car moving along said guide rail; a speed governor installed at the upper end of the shaft; an speed governor rope suspended from said speed governor in said shaft in a circular fashion with its both ends coupled with said car, one side of said speed governor rope being wound on said transmission sheave; and a position detection apparatus actuated through rotation of said transmission sheave for detecting the position of said car.
In another aspect, in elevator, the mount structure is preferably disposed at the upper end of said shaft outside a path of said car.
In another aspect, the elevator preferably further comprises an adjustment plate attached to said mount structure, and an idler pulley attached to said adjustment plate, wherein said one side of the speed governor rope is wound on said idler pulley for adjusting a winding angle thereof with respect to said transmission sheave.
In another aspect, the elevator preferably further comprises a displaceable fastening apparatus for displaceably fastening an adjustment plate to said mount structure to displace the adjustment plate forward and backward with respect to said guide rail.
In the foregoing elevator, the mount structure may be disposed outside an elevation distance of the car at a final end of the shaft.
Also in the foregoing, there may be provided a position fastening apparatus for displaceably fastening an adjustment plate on which an idler roller is mounted in the direction thereof where it goes forward and backward with respect to the guide rail.
Further, in the foregoing there may be provided a on-car operation switch including an automated/manual changeover switch and a control board operable with actuation of the on-car operation for operating the car at a low speed to a position corresponding to the position detection apparatus disposed at an upper end of the shaft.
Other and further objects, features and advantages of the invention will appear more fully from the following description.